Retort-furnace.



W. E. FLETCHER.

RETORT FURNACE.

APPLICATION F|LED'1AN.3.1914.

Patented Oct. 12, 1915.

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' w. E. FLETCHER.

RETORT FURNACE.

APPLICATION FILED IAN. 3, IBM.

1,155.,595a Patented Oct. 12, 191.5.

2 $HEETSSHEE124 MN ncoacx 7 WILLIAM E. FLETCHER,'OF TAMAQUA, PENNSYLVANIA, ASSIGNOR TO ATLAS POWDER COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

RETORT-FURNACE.

Specification of Letters Patent.

- Patented Oct. 13.2, 1915.

Application filed January 3, 1914. Serial No. 810,236.

To all whom it may concern:

Be it known that I, lVlLLL-iiit E. FLETCHER, a citizen of the Unlted States, residing at Tamaqua, in the county of Schuylkill and State o'l Pennsylania, have invented oertain new and useful .lmprrwements in Re tort-liurnaces, of which the following is a specification.

The object of the invention is to provide a retort furnace, especially adapted for use in the distillation of nitric acid, wherein there is effected an economy in the consumption of fuel, and consequently in the application 01 heat to the retort such a distribution of heat units to the walls of the retort as to insure a uniform heating thereof, to secure the necessary reaction, while avoiding both the overheating of those portions of the retort above the-level of, and not protected by, the liquid, to produce decomposition, or the local cooling of such portions of the retort to produce condensation and hence re: ction of the acid on the metal, and thereby to ettcct a maximum yield of the product, with due regard to simplicityand economy of construction in the furnace and retort mounting. These objects are attained in the preferred embodiment of the inven tion by the approximate relative proportions of the retort and furnace; by the disposition of the {grate or source of heat supply relative to the retort and the draft outlet to the stack: by the direction of the draft or circi'ilation through the furnace relative to the retort; by the provision of means for securing the expansion of the gases and retardation ot the current. or flow of the products of combustion; by supporting the retort out of contact with the masonry walls of the furnace, but suliiciently close to the same to form therewith a blind passage or compartment, so'that the vaporous' contents ol the furnace are heated by convection or conduction; by the contraction or reduction of the cross sectional area of the passage betweenthe retort and the walls of the furnace toward the top thereof, by removing the products of combustion from the source of heat supply in a direction substantially parallel. to the outside surface of the retort and in a direction away from the upper portion of the retort, whereby there is produced a rclatiw and graduated attenuation or rarcfication of the gases or Vapors toward the upper portion of the retort, and

' by constructing the retort in such a manner as to allow for the unavoidable relative eX- pansion of its parts and provide for economical replacement of the portion thereof which is subjected to the maximum effects of the heat necessary for distillation.

It will be understood that while a preferred embodiment of the inrention is disclosed in the accompanying drawings, various changes in the form, proportions and minor details of construction may be resorted to without departing from the spirit of the invention.

In said drawings,l igure 1 represents a cross sectional View of the retort furnace showing the retort in elevation, and Fig.2 represents a longitudinal sectional view of the furnace and retort, and illustrating the normal course of the products ot combustion from the source of heat supply to the outlet leading to a stack (not shown).

In the constriu-tion illustrated. the retort H) is arranged in the upper portion of the furnace, which may be constructed of brick, concrete or other appropriate masonry, and in what may be termed for convenience, an oii'set or pocket. with reference to the course of the products ot'.comlmstion from the grate or source of heat supply 1i. to the outlet 1'2, which lattermay lead to any suitable staelt or drat't-indiicing means, while hetweeirthe source of heat supply and the outlet'lis arranged an enlarged expansion chamber 13 to el'l'ect an expansion and. retardation of the products of combustion in the passage thereof from said source of heat to the outlet. This arrangement insures a movement of the products of combustion from the source of heat supply along the under surface of the retort to the outlet of the furnace. and the direct application of the heat of the products of combustion solely to the bottom of the retort. whereby the deterioration of the retort is confined mainly to the bottom thereof. The retort shown is made sectional with the bottom section 10 separable from the upper portion 10 to provide for the renewal of the former, when required, without necessitating the re newal ot' the entire retort. and also to pro ride for a certain compensation due to any unavoidable inequality of expansion of the material constituting the retort. The botap proximat ly corresponding with that of the walls of the retort, Se that the heating thereof will correspond approXimately with that of the walls of the retort, or, if there is any difference, will be more rapid than that of the walls of the retort, to avoid the dis advantages incident to chilled spots or cooler Zones on the walls of the retort, which, in the ordinary operation of such devices, produce condensation of nitric acid and consequently destructive reaction on the metal Walls of the retort.

The sections 10 and 10 may be detachably secured together in any convenient way; as by providing their meeting edges with flanges, and using clamps to hold the flanges in contact; or by employing bolts and nuts for the same purpose, after first boring as many holes as may be needed in the flanges.

The usual outlets and means for charging and giving access to the interior of the retort are shown at 16, 17 and 18, respectively, the'connection of the casings r'ifthese outlets with the retort being indirect, to avoid affecting the expansion of the walls of the retort or the conduction of heat therefrom or thereto.

The chamber or pocket of the furnace in which the retort arranged is of a size proportionate to the dimensions of the retort, such to provide a comparatively restricted passage around the sides, ends and top i of the retort, whereby the heating ofthose portions of the retort is effected by convec- V tion, the draft from the source of heat sup ply to the outlet of the furnace being in a direction away from said passage, and serving, in a degree, to attenuate or rarefy the gases, and to a certain extent to neutralize the tendency of the heated gases to riseto the top of the furnace, and thereby overheat those portions of the retort which are above the level of the liquid contents of the retort} and which therefore are not protected by a said liquid contents. The effect of this arrangementis to insure a comparatively uniform heating of the retort walls to prevent ,the destructive and expensive"Eonsequences of decomposition and condensation of the product.

What is claimed is:

1. A retort furnace wherein the course of the products of combustion om the source.

- the products of combustion from the source of heat supply to the outlet is downward, and wherein the retort is located above the source of heat supply.

A retort furnace having its source of heat supply and its outlet at opposite sides of the furnace and having theretort. in a pocket above and out of the course of the products of combustion from the source of heat supply to the outlet, and separated from the walls of the furnace to form a blind passage.

. fl. retort furnace having its source of heat supply and its outlet at opposite sides of the furnace and having the retort in a pocket above and out of'the course of the products of combustion from the source of heat supply to the outlet, and separated from the walls of the furnace to form a blind" passage, an enlarged, expansion chamber being provided beneath the retort and between the source of heat supply and the outlet. i

5. A retort furnace having the retoi-t located in i. pocket out of the course of the products of combustion from the. source of heat supply to the outlet and separated from the walls of the furnace .to form a blind passage in commhnication with the space connecting the source of heat supply with said outlet.

6. A retort having a separable bottom section, and supporting devices engaged and in contact with the upper section thereof.

7. A retort furnace having supporting girders, a retort having a body portion with projections resting on said girders, and a detachable bottom portion secured to the body portion below the girders, and means connected with the retort for giving access .to both of said portions.

In testimony whereof I ailix my signature in presence of twowvitnesses.

. lVlLLlAM E. FLETCHER. \Vitnesses:

C. E. KING, Tnoams J. LAFFEY. 

